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/* Problem: Directory file view ui. Files can be sorted by different properties (name, size, ...). Ui itself only needs elements
            that are currently in the visible section of the list view from x to y So I want to use a fixed size buffer with up to k elements 
            and walk through all files in the directory and only have the final elements between index x and y in the end in the fixed size buffer.
            Temp buffers are fine for me as long as they have a fixed at compile time size. For those familiar with SQL basically this is
            a SORT BY LIMIT begin, count.
             
  Idea:     Use Floyd–Rivest algorithm with average O(n) to find the x and y values. Walk over list again and fill fixed size k buffer with elements greater
            than x and smaller than y. Then just sort the k values in k*log(k). So we have O(n) + k*log(k)
            
  Problem:  Find x and y is not directly possible since not all elements are in memory because we have only fixed size buffer. 

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// Selection algorithm
// Partial sorting

// http://www.unicode.org/Public/UCD/latest/ucd/CaseFolding.txt
switch(rune) {
case 0x0041: return 0x0061; // LATIN CAPITAL LETTER A
case 0x0042: return 0x0062; // LATIN CAPITAL LETTER B
case 0x0043: return 0x0063; // LATIN CAPITAL LETTER C
case 0x0044: return 0x0064; // LATIN CAPITAL LETTER D
case 0x0045: return 0x0065; // LATIN CAPITAL LETTER E

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>

#define szof(a) ((int)sizeof(a))
#define cntof(a) ((int)(sizeof(a) / sizeof((a)[0])))

static void

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#include <stdio.h>
#include <limits.h>

#define byte4_dup(c)        (((c)<<24u)|((c)<<16u)|((c)<<8u)|(c))
#define byte4_cmp_lt(x,n)   (((x)-~0UL/255u*(n))&~(x)&~0UL/255u*128u) // x>=0; 0<=n<=128 
#define byte4_cmp_gt(x,n)   (((x)+~0UL/255*(127-(n))|(x))&~0UL/255*128) // x>=0; 0<=n<=127 

#ifdef _MSC_VER
static int bit_ffs32(unsigned int u) {_BitScanForward(&u, u); return (int)(u);}
static int bit_fls32(unsigned int u) {_BitScanBackward(&u, u); return 31-(int)(u);}

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#ifdef _MSC_VER
#define alignto(x) __declspec(align(x))
#define bit_cnt(u) __popcnt(u)
#define bit_cnt64(u) __popcnt64(u)
static int bit_ffs32(unsigned int u) {_BitScanForward(&u, u); return casti(u);}
static int bit_ffs64(unsigned long long u) {_BitScanForward64(&u, u); return casti(u);}
#else /* GCC, CLANG */
#define alignto(x) __attribute__((aligned(x)))
#define bit_cnt(u) __builtin_popcount(u)
#define bit_cnt64(u) __builtin_popcountll(u)

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#define xglue(x, y) x##y
#define glue(x, y) xglue(x, y)
#define uniqid(name) glue(name, __LINE__)

#ifdef _MSC_VER
#define swap(a,b) do { decltype((a) + 0) _t = (a); (a) = (b); (b) = _t; } while(0)
#else
#define swap(a,b) do {__typeof__((a) + 0) _t = (a); (a) = (b); (b) = _t; } while(0)
#endif

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/**
 * Advent of Code 2022
 * Day 2: Rock Paper Scissors
 * https://adventofcode.com/2022/day/2
 *
 * http://codercorner.com/Modulo3.htm
 * (Index+1)%3 = (1 << Index1) & 3
 */
#include <stdlib.h>
#include <stdio.h>

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static void
qdiag(float *restrict qres, const float *restrict A) {
  /* Diagonalizer: http://melax.github.io/diag.html
    'A' must be a symmetric matrix.
    Returns quaternion q such that corresponding matrix Q 
    can be used to Diagonalize 'A'
    Diagonal matrix D = Q * A * Transpose(Q);  and  A = QT*D*Q
    The rows of q are the eigenvectors D's diagonal is the eigenvalues
    As per 'row' convention if float3x3 Q = q.getmatrix(); then v*Q = q*v*conj(q)
  */

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/* 
Enable FMA support:
    clang -O2 -Wall -mfma
*/
static inline float
rsqrta(float x) {
  /* Exact bits: 13.71 */
  /* δ+max = 7.459289×10^−5 */
  /* δ−max = −7.450387×10^−5 */
  union { float f; int i; } v = {x};

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#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <float.h>
#include <string.h>
#include <assert.h>
#include <stdint.h>
#include <stdarg.h>
#include <math.h>